Chemical element

elementelementschemical elementselementalchemicalPure elementThe Elements118 chemical elements92 known elementsatomic element
A chemical element is a species of atom having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).wikipedia
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Atom

atomsatomic structureatomic
A chemical element is a species of atom having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).
An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element.

Oxygen

OO 2 molecular oxygen
For example, the atomic number of oxygen is 8, so the element oxygen consists of all atoms which have 8 protons. Iron is the most abundant element (by mass) making up Earth, while oxygen is the most common element in the Earth's crust.
Oxygen is the chemical element with the symbol O and atomic number 8.

Atomic number

proton numberZatomic numbers
A chemical element is a species of atom having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).
The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element.

Isotope

isotopesisotopicisotopic composition
There are 80 elements that have at least one stable isotope and 38 that have exclusively radionuclides, which decay over time into other elements.
Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.

Synthetic element

syntheticartificial elementsynthesized
One hundred eighteen elements have been identified: the first 94 occur naturally on Earth, and the remaining 24 are synthetic elements.
A synthetic element is one of 24 chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor or particle accelerator, or explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made".

Iron

FeFe 2+ Fe(III)
Iron is the most abundant element (by mass) making up Earth, while oxygen is the most common element in the Earth's crust.
Iron is a chemical element with symbol Fe (from ferrum) and atomic number 26.

Proton

protonsH + p
A chemical element is a species of atom having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).
Since each element has a unique number of protons, each element has its own unique atomic number.

Abundance of elements in Earth's crust

Earth's crustmost abundant element in the Earth's crustat relatively trace concentrations of parts per million each
Iron is the most abundant element (by mass) making up Earth, while oxygen is the most common element in the Earth's crust.
The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each chemical element shown as mg/kg, or parts per million (ppm) by mass (10,000 ppm = 1%).

Hydrogen

HH 2 hydrogen gas
The two lightest elements, hydrogen and helium, were mostly formed in the Big Bang and are the most common elements in the universe.
Hydrogen is the chemical element with the symbol H and atomic number 1.

Helium

Hehelium IIsuperfluid helium
The two lightest elements, hydrogen and helium, were mostly formed in the Big Bang and are the most common elements in the universe.
Helium (from ἥλιος) is a chemical element with the symbol He and atomic number 2.

Lithium

Lilithium ionLi +
The next three elements (lithium, beryllium and boron) were formed mostly by cosmic ray spallation, and are thus rarer than heavier elements.
Lithium (from λίθος) is a chemical element with the symbol Li and atomic number 3.

Beryllium

Be 7 BeBerillium
The next three elements (lithium, beryllium and boron) were formed mostly by cosmic ray spallation, and are thus rarer than heavier elements.
Beryllium is a chemical element with the symbol Be and atomic number 4.

Boron

Bboron-10 10 B
The next three elements (lithium, beryllium and boron) were formed mostly by cosmic ray spallation, and are thus rarer than heavier elements.
Boron is a chemical element with the symbol B and atomic number 5.

Big Bang

Big Bang theoryThe Big Bangbig-bang
The two lightest elements, hydrogen and helium, were mostly formed in the Big Bang and are the most common elements in the universe.
The model describes how the universe expanded from a very high-density and high-temperature state, and offers a comprehensive explanation for a broad range of phenomena, including the abundance of light elements, the cosmic microwave background (CMB), large-scale structure and Hubble's law (the farther away galaxies are, the faster they are moving away from Earth).

Silicon

Sisilicon revolutionsilicium
The high abundance of oxygen, silicon, and iron on Earth reflects their common production in such stars.
Silicon is a chemical element with the symbol Si and atomic number 14.

Stellar nucleosynthesis

hydrogen burningnucleosynthesisstellar fusion
Formation of elements with from 6 to 26 protons occurs in main sequence stars via stellar nucleosynthesis.
Stellar nucleosynthesis is the creation (nucleosynthesis) of chemical elements by nuclear fusion reactions within stars.

Cosmic ray spallation

Spallationcosmic rayspallation reactions
The next three elements (lithium, beryllium and boron) were formed mostly by cosmic ray spallation, and are thus rarer than heavier elements.
Cosmic ray spallation, also known as the x-process, is a set of naturally occurring nuclear reactions causing nucleosynthesis; it refers to the formation of chemical elements from the impact of cosmic rays on an object.

Supernova nucleosynthesis

supernovaduring supernovaeexplosive
Elements with greater than 26 protons are formed by supernova nucleosynthesis in supernovae, which, when they explode, blast these elements as supernova remnants far into space, where they may become incorporated into planets when they are formed.
Supernova nucleosynthesis is the nucleosynthesis of chemical elements in supernova explosions.

Chemical substance

chemicalchemicalssubstance
The term "element" is used for atoms with a given number of protons (regardless of whether or not they are ionized or chemically bonded, e.g. hydrogen in water) as well as for a pure chemical substance consisting of a single element (e.g. hydrogen gas).
Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds.

Radionuclide

radioisotoperadioisotopesradionuclides
There are 80 elements that have at least one stable isotope and 38 that have exclusively radionuclides, which decay over time into other elements.
All chemical elements can exist as radionuclides.

Native element minerals

native elementsNative mineralsnative
Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur.
Native element minerals are those elements that occur in nature in uncombined form with a distinct mineral structure.

Copper

CuCu 2+ cupric
Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur.
Copper is a chemical element with the symbol Cu (from cuprum) and atomic number 29.

Silver

Agsilver orenative silver
Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur.
Silver is a chemical element with the symbol Ag (from the Latin argentum, derived from the Proto-Indo-European h₂erǵ: "shiny" or "white") and atomic number 47.

Gold

Aunative goldgold dust
Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur.
Gold is a chemical element with the symbol Au (from aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally.

Carbon

Ccarbonaceouscarbon atom
Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur.
Carbon (from carbo "coal") is a chemical element with the symbol C and atomic number 6.